Disclosed is an air cleaner capable of removing contaminants in the air by using various air cleaning methods. The air cleaner includes a case including an upper opening through which air is introduced, a lower opening through which purified air is discharged, a filter module detachably mounted in the case and configured to filter out contaminants in the air, an injector injecting water, and an electric dust collecting device located below the injector and collecting dust in the air.